Feminist campaigners threw a New Year’s Eve party last night, marking the last day of women’s paid work for the year.

Equal Pay Day — instituted by the Fawcett Society to illustrate the huge gap between men’s and women’s wages — took place three days earlier this year, widening for the first time in half a decade.

And researchers warn that the trend is set to continue if action isn’t taken.

Young Labour women’s officer Beth Miller decided that the day was essentially the end of a woman’s year, so put on the New Year’s bash with help from the Fabian Women’s Network and Fawcett Society.

“We wanted to highlight the issue and bring it into people’s attention and we thought this was a good way to do it,” she told the Star.

“It’s bad that the pay gap is getting worse — this government has failed to bring it down.”

And she pointed out that with the gap widening four decades after the Equal Pay Act “we are actually going backwards.”

A Fawcett Society report published today shows the gender pay gap rising to a staggering 15.7 per cent, with women earning almost £5,000 less than men a year.

And while most men will have earned a total of £1 million by the age of 51, women have to work well into their 70s to earn the same.

The report said child-rearing and the unequal division of care work remained a major pull on women’s wages.

Women aged between 22 and 29’s pay is 4 per cent lower than men the same age, but this rises drastically to 11 per cent in the 30 to 39 age range and is 24 per cent for women in their 40s.

Fawcett deputy CEO Dr Eva Neitzert said: “The UK is fast sliding down the rankings of gender equal societies and we need to take action now.

“We urgently need action to tackle low pay, with the majority (62 per cent) of those paid below the living wage female.”

Last week, the World Economic Forum revealed that Britain had dropped from 18th to 26th in their ranking of gender-equal societies.

Fourteen European countries lie above Britain in the table, while the country is also trailing behind the US, Rwanda and Nicaragua in its treatment of women.

The women’s rights charity argued for a rise in the national minimum wage as it could help close the gender pay gap.

Rallying also for more equal distribution of care responsibilities, Dr Neitzert suggested: “The public sector should lead by example and advertise all vacancies on a flexible basis.”

But with the dismantling of the public sector — where the pay gap is closer — the situation will worsen.

With only low-waged and precarious employment growing the charity forecasts a further increase in the gap between men and women’s pay given how feminised these sectors’ workforces are.